1. Field of the Invention
The present invention is generally in the field of wireless communication systems. More specifically, the invention is in the field of wireless communication systems related to the Global System for Mobile Communications (GSM)/Enhanced Data for Global Evolution (EDGE) standards.
2. Background Art
In wireless communication systems multiple users may share a common communication channel. Some allocation of the available channel capacity to the users is typically made in order to avoid conflicts arising from multiple users transmitting information over the communication channel simultaneously. Allocation of user access to the communication channel is achieved by various forms of multiple access protocols.
For example, the GSM/EDGE standards utilize a protocol commonly referred to as time division multiple access (TDMA). In a TDMA system, a user's communication signal is transmitted in a uniquely assigned time slot. The time slots of the respective users do not overlap so that a given user's signal is separated from those of other users.
In a conventional GSM/EDGE system, a base station wirelessly transfers data to a mobile station (e.g. a handset) to inform the mobile station of the configuration of the link. From a portion of that data the mobile station determines the format in which it is to send data in the next interval back to the base station. A given EDGE data block comprises four bursts with one burst per frame. A given EDGE data block includes an uplink status flag (USF) codeword, as is known to those of ordinary skill in the art. There are eight possible USF codewords defined for EDGE, each comprising 36 bits. A USF codeword is used by the base station to inform the mobile station how to configure its uplink for the next transmission period.
In a GSM/EDGE system, four bursts are sent consecutively from the base station to the mobile station. A portion of each burst comprises USF data. The mobile station receives and decodes the data, determining what its transmission configuration should be for the following frame. The mobile station typically has less than about 4.615 milliseconds (ms) to decode the USF data and start transmitting data. Thus, a peak load is imposed on the wireless communication system.
The mobile station should act on the data contained in the USF codeword in the first frame subsequent to the reception of USF data. Thus, the USF data should be promptly decoded. Conventionally, the time interval available for decoding a USF codeword is relatively small. Consequently, schedule bottlenecks typically occur in a digital signal processor (DSP) of a conventional wireless communication system.
Thus, it is seen that there is need in the art for an improved method and system for communicating in EDGE/GSM. The system and method should allow for a relatively low error rate, while reducing schedule bottlenecks.